NOTE: This setting should be only used by developers.
Most shops should leave this option blank. The default behavior of the "Add to Cart Pop-up" feature is to trigger when a visitor clicks the "Add to Cart" button on the product page. In rare cases, a shop might need to specify an element (css selector) to be clicked in order to trigger the pop-up.
To change the trigger element, navigate to Settings -> Quickview & Popup Settings -> Add to Cart Pop-up -> Advanced -> Trigger Element
The trigger element must be a css selector. Examples:
When in doubt, open a ticket and our support team can advise.